IMPACT OF FEED RATE ON ROUGHNESS OF THE CUT SURFACE AND ENERGY CONSUMPTION DURING CUTTING DRY BEECH WOOD WITH A CIRCULAR SAW

Abstract

The feed rate during mechanical processing of wood is one of the factors that has a high influence on the roughness of the cut surface and energy consumption.
The roughness of the cut surface caused by traces of the cutting tool has an influence on the hydrothermal treatment and all other mechanical treatments of the wood. Greater roughness, due to faster evaporation of moisture from the wood, increases the percentage of drying errors. On the other hand, higher roughness values decrease the lumber yield.
Energy consumption is an indicator of the cutting resistance and it depends directly proportionally, or inversely proportionally when the thickness value of the sawdust is less than 0.1 mm. At the same time, the teeth do not cut the wood and they do not create sawdust but wood dust.
In this research, three different feed rates were applied (U1=12 m·min-1, U2=16 m·min-1 and U3=20 m·min-1) for a constant cutting height of 45 mm in dry beech wood with moisture content W=10±1%. The measurements were made with a circular saw with diameter of cutting tool D=250 mm, number of teeth Z=40 and width of the cut b=3,2 mm. The number of rounds was n=5500 min-1.
Roughness measurements were taken with a digital comparator, according to the Rmax criterion.
Measurement data for energy consumption were taken with a clamp amperemeter.
The obtained results showed a pronounced significance, directly proportional dependence of the roughness of the cut surface and energy consumption on the feed rate.